Review on 🐠 Efficient FREESEA Aquarium Heater with Submersible Thermometer - Choose from 25/50/100/200/300 Watts! by Melissa Sanchez

At first I was afraid to buy this heater, but the one recommended to me is too big for our aquarium, so I went for it and I'm still not wrong. We keep it about 3-5 degrees colder than I would like my tank to be based on all the reviews that it "cooks" people's fish. Started at the temp the tank was originally at (74) and it seemed to be heating up all the time so I increased it to 80 and it in turn heated the tank to 83 which I know is too hot for bettas . So I lowered it to about 75-77 and the tank stays at 78/79. I don't use the thermometer that came with the tank (we have the decorative one which my daughter loved) and keep it near the heater so it doesn't overheat the tank. I think it depends on how big your tank is (we have 3 gallons) and if it's glass or acrylic. I highly recommend getting one before catching your fish if you can. and if you're not running it at your tank temp, turn it on SLOWLY. Wait at least 24-48 hours before raising the temperature if it is not warm enough. The knob is difficult to turn and wasn't as stiff, and the readings are a bit vague and not very specific, but once we got them at the right time, they were consistent. My Betta also likes to hide around him and it doesn't seem to bother him at all or damage his fins. I would recommend this for tanks of 5 gallons or less.